Role of long-form PDGF A-chain in the growth of vascular smooth muscle cells from spontaneously hypertensive rats

Vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) exhibit exaggerated growth relative to cells from normotensive Wistar-Kyoto (WKY) rats. Platelet-derived growth factor (PDGF) A-chain has been implicated in the exaggerated growth of VSMC from SHR. Two isoforms of PDGF A-chain mRNA that either include (long form) or exclude (short form) exon 6 are produced as a result of alternative splicing. The expression of the long-form PDGF A-chain at the mRNA level and its role in the growth of VSMC from SHR have now been investigated with the use of an antisense oligodeoxynucleotide (ODN) complementary to exon 6 of the PDGF A-chain gene. Reverse transcription-polymerase chain reaction (RT-PCR) analysis with primers encompassing exon 6 of PDGF A-chain mRNA revealed bands corresponding to both long- and short-form PDGF A-chain transcripts in quiescent VSMC from both SHR and WKY rats, with the long-form mRNA more abundant in VSMC from SHR than in cells from WKY rats. Expression of the long-form of PDGF A-chain mRNA was enhanced with angiotensin II and transforming growth factor-beta1 in VSMC from SHR, but not in cells from WKY rats. The antisense ODN significantly inhibited DNA synthesis by VSMC from SHR, but not by cells from WKY rats, in the absence or presence of serum. In addition, the antisense ODN significantly inhibited serum induced proliferation of VSMC from SHR, but not those from WKY rats. The antisense ODN abolished expression of the long-form PDGF A-chain mRNA in VSMC, suggesting that its inhibitory effects on the growth of VSMC from SHR are mediated by depletion of the long-form transcripts. These results indicate that the long-form of PDGF A-chain contributes to the exaggerated growth of VSMC from SHR.

Gene transfer into the carotid artery using an adventitial collar: comparison of the effectiveness of the plasmid-liposome complexes, retroviruses, pseudotyped retroviruses, and adenoviruses

We studied the efficiency of plasmid/liposome complexes, Moloney murine leukemia virus-derived (MMLV) retroviruses, pseudotyped vesicular stomatitis virus protein-G (VSV-G)-containing retroviruses, and adenoviruses in delivering genes into the rabbit carotid artery using a silastic collar applied to the adventitia. This method was used for gene transfer because (a) it provides a gene delivery reservoir; (b) no intraluminal manipulations are performed; (c) installation of the collar induces arterial smooth muscle cell (SMC) proliferation and enhances retroviral gene transfer efficiency where target cell proliferation is required. The transfer of the beta-galactosidase (lacZ) marker gene to the adventitia and media occurred with all gene transfer systems. Adenoviruses also transferred the beta-galactosidase gene to some endothelial cells. After 5 days, adenoviral vectors produced the highest gene transfer efficiency with up to 10%+/-6% of cells showing beta-galactosidase activity. Pseudotyped VSV-G retroviruses were also effective in achieving gene transfer in 0.05%+/-0.03% of cells in the adventitia and media. Plasmid/liposome complexes and MMLV retroviruses infected 0.05%+/-0.03% and <0.01%+/-0.01% of cells, respectively. It is concluded that replication-deficient adenoviruses, VSV-G pseudotyped retroviruses, and plasmid/liposome complexes can be used for gene transfer to the arterial wall using the collar method. Because the endothelium remains anatomically present throughout the experiments, the model may be useful for the gene transfer studies involving diffusible or secreted gene products that primarily act on the endothelium. Effects on medial SMC and even endothelium can be achieved from the adventitial side, suggesting an alternative route for the delivery of therapeutically useful genes into the arterial wall.

Histogenesis of hollow cell ball structure of ovarian and endometrial adenocarcinoma cells in vivo and in vitro

Hollow cell ball structure is often found in the ascites of adenocarcinoma patients. How to form a hollow cell ball structure was studied in vivo and in vitro, using the human cell lines derived from ovarian and endometrial adenocarcinomas. The hollow cell ball structure was formed by horizontal rotation culture of 1 x 10(7) single-suspended cells for 24 hours or by transplanting 1 x 10(6) single-suspended cells into the peritoneal cavity of nude mouse for 24 hours. At one month after transplantation hemi-cyst and hollow cell ball structure were formed in the outermost layer of the grafted tumor on the intraperitoneal serous membrane in the nude mouse. And also great number of floating hollow cell ball structure in the ascites were observed. These results suggest that mechanisms of formation of hollow cell ball structure found in the ascites; one by cell aggregate of single cells, sometimes inner cells of cell aggregate fall into necrosis or secretes mucus inside and make a hollow cell ball structure and another by the removed as the hollow cell ball structure grown from hemi-cyst on the surface of intraperitoneal grafted tumor.

Tissue reconstruction of gynecologic tumor cells in the rotation culture system

Tissue reconstruction of various kinds of gynecologic malignant tumor cell lines was studied using the rotation-culture system. The reconstructed cell aggregates were examined histologically using both light and electron microscopy. Our established cell lines used in this study were uterine cervical epidermoid carcinoma, endometrial adenocarcinoma, ovarian malignant tumor and uterine sarcoma. All of the reconstructed aggregates from each cell line were very similar to the original tumor tissue. In the case of a well differentiated type of adenocarcinoma derived from the ovarian cancers or the endometrial cancers, papillary cell aggregates (grape-like structures) and/or hollow cell ball (gland alveolus-like) structures were observed. The individual cells were adjoined with by desmosomes and well developed microvilli protruded from the free surface of the cells. On the other hand large cell non-keratinizing squamous cell carcinoma cells formed spherical-shaped aggregates that showed a stratified structure similar to pearl formation. Sarcoma cells formed solid clusters while desmosomes or desmosome-like junctions were not detected. Rotation culture is an excellent method to reveal diagnosis of the original tumor and tumorigenesis by investigating a reconstructed tissue from peritoneal effusions because the reconstructed tissue is similar to the original tumor.

Association analysis of TG repeat polymorphism of the neuronal nitric oxide synthase gene with essential hypertension

The nitric oxide synthase (NOS) gene is thought to be involved in essential hypertension because nitric oxide is implicated in endothelium-mediated or nitroxidergic neuron-mediated vasodilation. Using simple tandem repeat DNA polymorphism of the neuronal constitutive NOS (nNOS) gene, we carried out an association study in patients with essential hypertension. One hundred and thirty-one patients with essential hypertension and 147 subjects with normal blood pressure were studied. Polymerase chain reaction was applied to amplify the TG repeat site in the nNOS gene, and alleles based on the TG repeat number were determined. Eight alleles were identified in this study of Japanese subjects. Overall distributions of allele frequencies in the two groups were not significantly different. Thus, the genes detected by examination of this microsatellite polymorphism in the nNOS gene are not associated with essential hypertension.

Eicosapentaenoic acid enhances nitric oxide production by cultured human endothelial cells

It is unclear whether the abnormal relaxation seen in diabetes is due to decreased levels of nitric oxide (NO) and how eicosapentaenoic acid (EPA, C20:5 omega 3) affects the endothelial production of NO. We investigated the effects of EPA ethyl ester (EPA-E) and elevated glucose on NO production by human endothelial cells (HUE). EPA-E (0.3 mM) significantly enhanced [NO2] production and the intracellular concentration of free Ca2+ within 3 min after EPA-E was added to the cultures. High levels of glucose (27.5 mM) significantly increased endothelial glucose, sorbitol and fructose, and inhibited [NO2-] production. However, EPA-E (0.3 mM) prevented the inhibition of [NO2-] production due to the activation of the Ca(2+)-calmodulin system of NO synthase. EPA-E decreased the glucose-mediated inhibition of NO production by HUE. These results suggest this agent might ameliorate endothelial dysfunction associated with diabetes.

Secretory processing of amyloid precursor protein is inhibited by increase in cellular cholesterol content

Plasma-membrane composition plays a crucial role in most of the cellular functions that depend on membrane processes. In virtually all cell types the proteolytic processing of Alzheimer amyloid precursor protein (APP) to generate soluble APP (sAPP) is believed to occur at the plasma membrane or in its immediate proximity. Alteration of this metabolic pathway has been linked to the pathogenesis of Alzheimer's disease. We analysed the effect of membrane cholesterol enrichment on APP metabolism. Incubation of COS cells with increasing concentrations of non-esterified cholesterol carried by rabbit beta-very low-density lipoprotein caused a dose-dependent inhibition of sAPP release: 70% inhibition with 10 microg/ml non-esterified cholesterol. A less pronounced inhibitory effect was observed on treatment with human low-density lipoprotein. Inhibition of sAPP release was independent of receptor-mediated lipoprotein metabolism since simultaneous treatment with chloroquine did not modify the effect of lipoprotein treatment. In addition, treatment with cholesterol dissolved in either ethanol or methyl-beta-cyclodextrin elicited the same effect. Excess non-esterified cholesterol did not cause cell toxicity. Cell cholesterol mass inversely correlated with sAPP release. Progesterone, which inhibits shuttling of non-esterified cholesterol between the plasma membrane and intracellular pools, had no effect on the inhibition of sAPP release from cholesterol-loaded cells, providing indirect evidence that cholesterol may act at the plasma membrane.

Inhibitory effects of omega-3 polyunsaturated fatty acids on receptor-mediated non-selective cation currents in rat A7r5 vascular smooth muscle cells

1. The effects of omega-3 polyunsaturated fatty acids on receptor-mediated non-selective cation current (Icat) and K+ current were investigated in aortic smooth muscle cells from foetal rat aorta (A7r5 cells). The whole-cell voltage clamp technique was employed. 2. With a K(+)-containing solution, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA, 30 microM) produced an outward current at a holding potential of -40 mV. This response was inhibited by tetraethylammonium (20 mM) or Cs+ in the patch pipette solution, and the reversal potential of the EPA-induced current followed the K+ equilibrium potential in a near Nernstian manner. 3. Under conditions with a Cs(+)-containing pipette solution, both vasopressin and endothelin-1 (100 nM) induced a long-lasting inward current at a holding potential of -60 mV. The reversal potential of these agonist-induced currents was about +0 mV, and was not significantly altered by the replacement of the extracellular or intracellular Cl+ concentration, suggesting that the induced current was a cation-selective current (Icat). 4. La3+ and Cd2+ (1 mM) completely abolished these agonist-induced Icat, but nifedipine (10 microM) failed to inhibit it significantly. 5. omega-3 polyunsaturated fatty acids (3-100 microM), EPA, DHA and docosapentaenoic acids (DPA), inhibited the agonist-induced Icat in a concentration-dependent manner. The potency of the inhibitory effect was EPA > DHA > DPA, and the half maximal inhibitory concentration (IC50) of EPA was about 7 microM. 6. Arachidonic and linoleic acids (10, 30 microM) showed a smaller inhibitory effect compared to omega-3 fatty acids. Also, oleic and stearic acids (30 microM) did not show a significant inhibitory effect on Icat. 7. A similar inhibitory action of EPA was observed when Icat was activated by intracellularly applied GTP gamma S in the absence of agonists, suggesting that the site of action of omega-3 fatty acids is not located on the receptor. 8. These results demonstrate that omega-3 polyunsaturated fatty acids can activate a K+ current and also effectively inhibit receptor-mediated non-selective cation currents in rat A7r5 vascular smooth muscle cells. Thus, the data suggest that omega-3 fatty acids may play an important role in the regulation of vascular tone.

CA repeat polymorphism of the neuronal nitric oxide synthase gene

CA repeat polymorphism in the neuronal nitric oxide synthase gene was studied by the polymerase chain reaction. The distribution of allele frequencies in Japanese subjects was determined.

[Study of serum thrombomodulin(TM) levels in patients with hyper- or hypo- thyroidism]

We studies a relationship between the serum levels of thrombomodulin(TM) and the thyroid functions. Serum TM levels were measured in 48 patients with Graves' disease, 17 patients with primary hypothyroidism, 7 patients with subacute thyroiditis, 5 patients with painless thyroiditis and 2 patients with systematic Refetoff syndrome. These patients did not have malignant tumor, kidney failure, or blood vessel injury. Control sera were obtained from 42 healthy subjects. Serum levels of TM in patients with untreated Graves' disease were significantly higher(p < 0.001) compared with those in controls. Serum levels of TM in patients with hypothyroidism were not significantly changed as compared with those of controls. There were a positive correlation between the serum levels of TM and FT3 as well as FT4. Serial determinations of the serum levels of TM and thyroid function(FT3, FT4 and TH) in patients with Graves' disease during treatment showed that both the serum levels of TM and thyroid hormones (FT3 and FT4) lowered progressively during treatment. After normalization of serum FT3 and FT4, the serum TM levels returned to normal. However, the serum levels of TM in patients with destructive thyroiditis and Refetoff syndrome were normal in spite of high serum levels of thyroid hormones. These data suggest that an increase in serum levels of TM is not the direct result of thyroid hormones themselves but is the result of the prolonged hypermetabolic state induced by their peripheral activities. Thyroid hormones may stimulate the synthesis or metabolism of TM on the surface of vascular endothelial cells in the patients with Graves' disease.

Effect of dibutyryl cyclic AMP on plasma renin activity in normal men and patients with primary aldosteronism

Dibutyryl cyclic AMP (DBcAMP) directly stimulates the release of renin from the juxtaglomerular (JG) cells in vitro. We investigated the effect of DBcAMP on plasma renin activity (PRA) in 6 normal men and in 8 patients with primary aldosteronism (PA). A 20-min infusion of 0.33 mg/kg/min of DBcAMP significantly increased PRA in normal men, but had little effect on PRA in patients with PA. Infusion of DBcAMP significantly reduced the blood pressure and the levels of serum sodium and potassium in normal men and the patients with PA. Infusion of DBcAMP significantly increased urine volume in normal men, but not in patients with PA. Urinary excretion of sodium increased in both groups after the infusion of DBcAMP. Thus, DBcAMP did not stimulate renin release in patients with PA, suggesting that the chronic excess production of aldosterone suppresses the release of renin from JG cells.

Association analysis of CA repeat polymorphism of the endothelial nitric oxide synthase gene with essential hypertension in Japanese

The nitric oxide synthase (NOS) gene is thought to be associated with essential hypertension (EH), because NO is implicated in endothelium-mediated vasodilation. We investigated the possible association between the alleles of simple tandem repeat DNA polymorphism of the endothelial constitutive NOS (cNOS) gene and EH in Japanese subjects. In all, 100 patients with EH and 123 subjects with normal blood pressure were studied. Polymerase chain reaction was used to amplify the CA repeat site in the endothelial cNOS gene and alleles based on the CA repeat number were determined. The allele frequencies in the hypertensive group and normotensive group were then compared. Twenty-three alleles were identified in this study of Japanese subjects. The overall distributions of allele frequencies in the two groups were not significantly different. However, comparing the allele frequencies in the EH group without left ventricular hypertrophy (LVH) and the normotensive group, the overall distributions were significantly different (p = 0.019). The 33-repeat allele was found more frequently in the EH group without LVH than in the normotensive group (p = 0.000047, Odds ratio = 3.71). In conclusion, the 33-repeat allele of the endothelial cNOS gene is associated with EH without LVH, and may be a genetic marker of EH in Japanese subjects.

Lipoprotein(a) and other lipids after oophorectomy and estrogen replacement therapy

OBJECTIVE

To assess the effect of surgical menopause and subsequent estrogen replacement therapy (ERT) on lipoprotein(a) [Lp(a)] and common lipids.

METHODS

In 24 healthy premenopausal women, lipids (total cholesterol, low-density lipoprotein [LDL] and high-density lipoprotein [HDL] cholesterol, and triglycerides) and gonadotropins (FSH, LH) were measured the day before hysterectomy with bilateral oophorectomy and then after 1, 2, and 3 months. Blood was also drawn after 2, 4, 6, and 15 days to exclude the effect of surgery on Lp(a). In 19 women who volunteered for ERT, the lipid profile was assayed again after 3, 6, and 12 months of treatment.

RESULTS

Lipoprotein(a) levels rose significantly over the 3 months after surgery, from a mean +/- standard deviation (SD) 5.7 +/- 6.1 mg/dL to 10.4 +/- 9.2 mg/dL. Total cholesterol and LDL cholesterol levels increased significantly over the first 2 months; HDL cholesterol decreased significantly during the 3 months of follow-up (by 10, 17, and 20%) (P < .001). Plasma triglycerides did not change after surgery. Three months following ERT, Lp(a) and total cholesterol were significantly decreased (28 and 11%, respectively), as was LDL cholesterol (33%) after 6 months. High-density lipoprotein cholesterol increased by 24% after 6 months of treatment, and triglycerides rose significantly in the year of therapy (37%).

CONCLUSION

These findings suggest that surgical menopause induces atherogenic changes in the lipid profile in 3 months and that ERT soon reverses them.

Prevention of cardiac hypertrophy by a sub-antihypertensive dose of the alpha 1-adrenergic antagonist bunazosin in Dahl salt-sensitive rats

To assess the protective effect of an alpha 1-blocker on the development of cardiac hypertrophy, the selective alpha 1-receptor antagonist bunazosin (2 mg/kg/d, by oral gavage and in drinking water) was given to male Dahl salt-sensitive rats fed a 4% NaCl diet for 7 weeks. Control animals received water only by the same method. Treatment with bunazosin was started when the animals were 7 weeks of age. Blood pressure, pulse rates, and body weight were measured every week during the experiment. Urine was collected for 24 h on the final day of the experiment. All animals were killed by decapitation, blood was collected, and the heart was removed. In both the treated and control groups, time-dependent increase in blood pressure and body weight were observed, and there were no significant differences between the groups in blood pressure or body weight during the experiment. Pulse rate remained unchanged in both groups throughout the experiment. The left ventricular weight/body weight ratio and the left ventricular tissue DNA content were significantly lower in the rats receiving bunazosin than in the control rats. Plasma renin activity, plasma aldosterone, and plasma atrial natriuretic peptide did not differ significantly between the two groups. No significant differences in glomerular filtration rate, urine volume, sodium excretion, urinary metanephrine excretion, and urinary normetanephrine excretion were noted between the two groups. The results indicate that a sub-antihypertensive dose of bunazosin can inhibit the development of cardiac hypertrophy without suppression of the pressure load, suggesting an important role of alpha 1-adrenergic receptors in the pathogenesis of cardiac hypertrophy following the development of hypertension.

[Studies on cerebrospinal fluid penetration of cefpirome in adult with meningitis]

A patient with intracerebral hematoma suffered from postoperative bacterial meningitis. Staphylococcus aureus was found from CSF. The organism was multiple drug resistant and refractory to antibiotics including piperacillin (PIPC), cephalexin (CEX), cefotaxime (CTX), ceftazidime (CAZ) and latamoxef (LMOX). It was susceptible to cefpirome (CPR). Treatment with CPR resulted in clinical improvement associated with clearing of the organism from CSF. Serum level of CPR was high enough and CPR penetration into the CSF was satisfactory. The results suggest that CPR is an extremely effective antibiotic for meningitis caused by CPR-susceptible bacteria. Evaluation of the CPR penetration into the CSF of adult meningitis was rarely reported. The result we obtained was important in the treatment for the adult meningitis.

Organization of the human prostacyclin synthase gene

We determined the exon/intron organization of the human prostacyclin synthase gene. The gene, which spans approximately 70 kilobases, is composed of 10 exons.

A nitric oxide synthesis inhibitor prevents the ACTH-stimulated production of aldosterone in rat adrenal gland

The synthesis of nitric oxide (NO) has been demonstrated in the vascular endothelial cells and other tissues including in rat and bovine adrenal gland. To determine whether NO mediates aldosterone production in the adrenals, we evaluated the basal production of aldosterone, and the ACTH or angiotensin II (A II)-stimulated aldosterone in the presence of L-NG monomethyl arginine (L-NMMA) or L-arginine or L-NMMA + L-arginine in isolated rat adrenal capsular tissue by an ex vivo perfusion technique. ACTH increased the release of aldosterone by 40%. Such release of aldosterone was inhibited by L-NMMA, but not by a mixture of L-NMMA and L-arginine. A II stimulated aldosterone release by 40%. The increase in aldosterone release in response to A II was inhibited by L-NMMA or L-arginine. The increase in aldosterone release stimulated by A II was also inhibited by L-NMMA with L-arginine. L-glutamine did not inhibit the A II stimulated aldosterone release. In conclusion, the inhibition of NO synthesis prevented the release of aldosterone stimulated by ACTH, suggesting NO is required for the action of ACTH on aldosterone production.

A nitric oxide synthesis inhibitor decreased prostaglandin production in rat mesenteric vasculature

Endothelial cells synthesize and release nitric oxide (NO) and prostacyclin (PGI2) which are involved in the regulation of vascular tone and blood pressure. Our objective was to evaluate the effects of inhibiting NO synthesis on vascular prostaglandin (PG) and cyclic nucleotide production, as well as the pressor response to norepinephrine (NE). Isolated mesenteric arterial beds were perfused with Krebs-Henseleit solution containing 100 microM NG-monomethyl-L-arginine (L-NMMA), 100 microM L-arginine (LA), or vehicle. After a 30 min equilibration 0.1, 0.5, 1, or 5 microM NE was infused into the superior mesenteric artery and the perfusion pressure was monitored. The basal perfusion pressure did not differ significantly between groups. The pressure-response curve was shifted to the right in the L-NMMA group vs. the LA and control groups. Perfusion was similarly performed with a Krebs-Henseleit solution containing 100 microM L-NMMA, LA, D-arginine, or vehicle. Perfusates were collected before and after NE infusion for the measurement of PGE2, 6-keto-PGF1 alpha, TxB2, cAMP, and cGMP. In the L-NMMA group the release of PGE2 and 6-keto-PGF1 alpha was decreased, and the release of cGMP was prevented. Production of cAMP did not differ between the four groups before NE infusion, and NE increased cAMP release in the L-NMMA group and controls. The results indicate that inhibition of NO synthesis by L-NMMA enhanced the pressor response to NE, possibly mediated by the decreased cGMP and PGI2 production in resistance vessels.

[Parasagittal meningioma growing in the superior sagittal sinus presenting intracranial hypertension: a case report]

Parasagittal meningiomas often invade the superior sagittal sinus (SSS), but rarely grow inside the SSS as a primary tumor. The authors report a case of parasagittal meningioma growing mainly inside the SSS and presenting papilledema. The SSS is invisible behind the tumor end on the right carotid angiogram but still patent on the left carotid angiogram. The superficial cortical vein on the opposite side works as a collateral pathway. The tumor may have originated from the right wall of the SSS, grew inside the sinus and covered the entrances of the right ascending cerebral veins. V-P shunt was performed after removal of the mass outside the sinus for resolving headache and visual symptoms.